Add seal word to plain normalisation regex

This update adjusts regular expression of PlainNormalizer to take into account the next possible names of the seal: qrcode.png, qrcode-xxx.png, seal-xxx.png Closes #https://code.vereign.com/seal/clients/chrome-extension/-/issues/34

dist/PlainNormalizer/PlainNormalizer.js

@@ -23,10 +23,16 @@ const patchOutlookSafelinksWrappers = (text) => {
     }
     return text;
 };
+/**
+ * Function removes seal from the plain text.
+ * Function has to support the next possible file names of the seal:
+ * qrcode.png, qrcode-xxx.png, seal-xxx.png
+ * @param s
+ */
 const removeQRCodes = (s) => {
     return s
-        .replace(/\[(image:\s)*qrcode.png]\s*<https:\/\/.+(vereign\.com|vrgnservices\.com).*?>/g, "")
-        .replace(/<https:\/\/.+(vereign\.com|vrgnservices\.com).*?>\s*\[(image: )*qrcode.png]/g, "");
+        .replace(/\[(image:\s)*(qrcode|seal).*?.png]\s*<https:\/\/.+(vereign\.com|vrgnservices\.com).*?>/g, "")
+        .replace(/<https:\/\/.+(vereign\.com|vrgnservices\.com).*?>\s*\[(image: )*(qrcode|seal).*?.png]/g, "");
 };
 const cleanupHiddenCharacters = (s) => {
     const removeSymbols = new RegExp(/[\u200B]+/g);